prereqs Dockerfile fails to build: bullseye release file is expired

net/grpc/gateway/docker/prereqs/Dockerfile cannot build. Both of its stages are on Debian 11, whose release file is expired, so apt-get update fails with exit code 100 on the first RUN.

#10 [prepare 2/9] RUN apt-get -qq update && apt-get -qq install -y curl unzip
#10 1.940 E: Release file for http://deb.debian.org/debian-security/dists/bullseye-security/InRelease is expired (invalid since 1d 8h 2min 24s).
#10 ERROR: process "/bin/sh -c apt-get -qq update && apt-get -qq install -y curl unzip" did not complete successfully: exit code: 100

To reproduce:

docker build -f net/grpc/gateway/docker/prereqs/Dockerfile .

Every image that builds FROM grpcweb/prereqs is blocked by this: binary_client, closure_client, commonjs_client, interop_client, node_server, echo_server, ts_prereqs, ts_client.

We hit it in eclipse-vertx/vertx-grpc, which builds this image to run the gRPC-Web interop tests: https://github.com/eclipse-vertx/vertx-grpc/actions/runs/34314125183/job/102346651634